World’s leading generics producer Teva Pharmaceutical Industries Limited is trying to block a generic version of glatiramer acetate from India’s Natco Pharma by filing a Citizen’s Petition with US FDA, alleged the Hydearabad based firm.

Teva of Israel has filed a Citizen Petition with the US FDA as a part of its effort to prolong its monopoly on Copaxone, which is used in the treatment of multiple sclerosis in the United States.

Teva had filed a Citizen Petition in 2008, as well. However, the petition was rejected by US FDA earlier this year.

Glatiramer acetate, which is marketed in the brand name Capaxone in US, is extremely important because it is the it is the largest product in Teva’s drugs portfolio.

Capaxone clocked in sales of around US$ 2262 million in 2008.

With the approval of glatiramer acetate generic injectable, global sales of the drug may reach as much as $3 billion this year.

Teva also received the USFDA approval for its abbreviated new drug application (ANDA) for glatiramer acetate Injection.

Copaxone is responsible for roughly 20% to 25% of Teva’s net profit, a proportion expected to increase after April 2010, which is when Teva will stop paying royalties to Sanofi-Aventis.

In April 2008 Teva and Sanofi-Aventis entered into a new agreement that gives Teva sole responsibility for marketing Copaxone in North America. But it agreed to continue to pay royalties to Sanofi-Aventis for two years.

Teva pays Sanofi Aventis a quarter of its Copaxone sales figures in North America as royalties, as part of a marketing pact signed in 1996. They share sales costs and gross profit for Copaxone in equal parts.

Capaxone’s share of the market is 32%, while rival drug Avonex made by Biogen Idec commands a 30% market share. Teva’s sales of Copaxone jumped 32% during the second quarter of 2009, against the same period of 2008, to $438 million.

Global sales of Copaxone grew by 21% in the second quarter year-over-year to $682 million.

Copaxone’s market share is 28% outside the United States, compared with 25% for Avonex.

Natco Pharma, in association with Mylan filed an abbrevited new drug application – ANDA for glatiramer acetate has been accepted for review by the US FDA in Septembe 2009 and the review is presently ongoing.

Teva had alleged that there is a significant difference between Natco’s product and its Copaxone.

Filing of a Citizen Petition is an attempt to delay the approval of the ANDA and this is a common tactic employed by the branded pharma companies in the USA to delay generic competition. Teva seems to have borrowed this manoevour from the branded pharma industry, Natco said.

For Natco, this product, on approval, represents a significant upside. Natco is the only generic producer in world having the technology to make glatiramer acetated which involves complex peptide chemistry, Natco said in a press note to Bombay Stock Exchange.

Natco intends to suitably respond to Teva’s unfounded claims, the company said.

In October, Teva Pharmaceutical Industries initiated legal proceedings against the commercialization of a generic version of its blockbuster glatiramer acetate (Capaxone) by Mylan and Natco, alleging that their application was infringing on certain patents in the U.S. District Court for the Southern District of New York.

The lawsuit could restrict approval of Mylan’s generic version of the drug for up to 30 months – April 2012 – or until a court ruling in favor of Mylan, whichever comes first.

Mylan’s application relates to Teva’s U.S. patents, which cover the chemical composition of the blockbuster drug, pharmaceutical compositions containing it, and methods of using it.

The patents are listed in the U.S. Food and Drug Administration’s Orange Book and extend through May 24, 2014, Teva said in a statement.

In 2008, Natco entered into a license and supply agreement with Mylan which granted Mylan exclusive distribution rights for glatiramer acetate pre-filled syringes in the US and all major markets in Europe, Australia, New Zealand, Japan and Canada. The agreement also included an option to potentially expand into additional territories.

Natco has already commercialized its glatiramer acetate product in India and the Ukraine.